1. Field of the Invention
The present invention relates generally to a pre-connectorized fiber optic distribution cable and, more particularly, to a factory-assembled fiber optic distribution cable having at least one predetermined mid-span access location for providing access to a plurality of optical fibers that are preterminated and pre-connectorized to a multifiber connector.
2. Description of the Related Art
Optical fiber is increasingly being used for a variety of broadband applications including voice, video and data transmissions. As a result, there is a need for connecting remote locations to a fiber optic distribution cable in order to provide broadband services to an end user, commonly referred to as a subscriber. In this regard, fiber optic networks are being developed that deliver “fiber-to-the-curb” (FTTC), “fiber-to-the-business” (FTTB), “fiber-to-the-home” (FTTH) and “fiber-to-the-premises” (FTTP), referred to generically as “FTTx.” networks. To provide these services to the subscriber, FTTx networks must include a large number of interconnection points, referred to herein as “tap points,” at which one or more optical fibers of a distribution cable are interconnected or mated to optical fibers of one or more cables leading to a subscriber location. In addition, in order to reduce installation labor costs in FTTx networks, communications service providers are increasingly demanding factory-prepared interconnection solutions, commonly referred to as “plug-and-play” systems.
To supply the large number of tap points needed and to satisfy the demand for plug-and-play systems, it is apparent that more efficient methods of providing mid-span access locations along the length of a distribution cable are needed. Presently, to perform a mid-span access of a distribution cable, a field technician first removes a section of the cable sheath at a convenient location along an installed distribution cable. Once the sheath is removed, the technician gains access to pre-selected optical fibers through the cable sheath, severs the accessed optical fibers and withdraws a useable length of the terminated optical fibers from the distribution cable. The useable length of the terminated optical fibers provides the field technician with sufficient length to splice one or more optical fibers of a cable comprising a lesser amount of optical fibers than the distribution cable (typically referred to as a “drop cable”) to the pre-selected optical fibers of the distribution cable. After splicing is completed, the mid-span access location is typically covered using an enclosure designed to protect the splices and the exposed section of the distribution cable. This time consuming process is typically accomplished by a highly skilled field technician at a significant cost and under less than ideal working conditions.
Several approaches have been developed to overcome the disadvantages of accessing, terminating and splicing optical fibers in the field. In one approach, the splicing of drop cables to the distribution cable is performed at a factory during the manufacturing of the cable. The preterminated distribution cable, including the main cable, drop cables and associated splice closures, are assembled and wound onto a cable reel to be delivered to an installation site. Accordingly, favorable conditions in the factory for making high quality splices may be utilized, thereby increasing splice quality and also reducing the expense, difficulty and unfavorable conditions associated with splicing in the field. One disadvantage of this approach is that the drop cables and the relatively bulky and inflexible splice closures are attached to the distribution cable prior to installation. Accordingly, installation through small diameter conduits and over sheave wheels and pulleys is substantially more difficult, and sometimes impossible. Another disadvantage is the fact that if a mid-span access location remains unused following installation, the obtrusive splice closure and drop cables remain attached to the distribution cable. In contrast, a low-profile distribution cable assembly having a pre-connectorized mid-span access location allows a field technician to readily interconnect drop cables and attach a closure to the distribution cable following installation and as the mid-span access location is needed to provide service to subscribers.
Accordingly, it would be desirable to provide a factory-assembled fiber optic distribution cable having one or more predetermined mid-span access locations along the length of the distribution cable for accessing a plurality of optical fibers that are preterminated and pre-connectorized to a multifiber connector wherein each such mid-span access location has an outer diameter that is only minimally larger than the outer diameter of the distribution cable. It would also be desirable to provide a pre-connectorized fiber optic distribution cable having one or more low profile mid-span access locations that is suitable for both buried installations (e.g., through small-diameter conduit) and aerial installations (e.g., over sheave wheels and pulleys). It would further be desirable to provide a factory-assembled pre-connectorized fiber optic distribution cable that is readily installed and adapted to be interconnected with pre-connectorized drop cables and configured with a variety of different closures in the field as needed.